This name is a synonym of Adiantum pedatum var. grandifolium (Ching) Ching.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 26617670) with original publication details: Bull. Fan Mem. Inst. Biol., n.s., 1: 268 1949.
This name was in version 1 of The Plant List, record tro-26617670, and has not been changed.